The objective of the proposed effort is to develop a nearly ideal, hand-held aerosol delivery system, based on the principles of ultrasonic atomization, to replace current metered dose inhalers. Ultrasonic atomization produces controlled narrow droplet size distributions and can be used with both solutions and suspensions. The narrow drop size distribution may reduce systemic effects because smaller doses can be used and a higher percentage of the drug will be delivered to the required sites rather than being deposited in the mouth and throat. Electronic control provides precise dose size to meet or exceed proposed stringent FDA regulations. Moreover, the ultrasonic-based system does not require a propellant, which will help manufacturers eliminate chlorofluorocarbon-based systems and will simplify formulation of their products. The feasibility of the device will be demonstrated in Phase I by designing and building a prototype and measuring its performance. Performance measurements to be made include measurement of drop size distributions, atomization delivery rate and dose repeatability as a function of system parameters. Achievement of these goals will produce a new aerosol delivery technique that can replace current metered dose inhalers and produce a higher level of performance and safety. PROPOSED COMMERCIAL APPLICATIONS The successful completion of this SBIR effort will produce a greatly improved aerosol delivery system which can be used for a wide range of solutions and suspensions. The ultrasonic device can replace many propellant-based or dry powder inhaler systems while providing better performance, e.g., tighter drop size distribution, better dose control, and greater ease of use.